1. Field of the Invention
The invention relates to communication networks. In particular, the invention relates to analyzing and monitoring for a communications network and its services in a novel and improved way.
2. Description of the Related Art
Today communications networks, such as mobile telecommunications networks, typically comprise a large number of various network elements including base stations, switching centers, various gateways etc. Typically a large communications network may comprise tens of thousands of network elements. And still the networks continue to grow as more and more services are developed.
To maintain, monitor and manage these large and complex networks, there have been developed network management systems in which network management information is collected. The information is typically received from Operation and Maintenance (O&M) units internal or external to a network element, or by probing with an external monitoring tool. Typically the collected information can be presented to network management personnel or operators in various ways to facilitate an operator to make informed management decisions. Typically the collected information is numerical and it is also presented in a numerical form. That is, e.g. a measured piece of numerical performance data is typically presented to the network management personnel as is.
Typically a network management system comprises fault management and performance management. Fault management involves monitoring notifications and alarms generated by various network elements, O&M units and the network management system itself, indicating status changes and detected faults, evaluating their importance and effects, and initiating actions, like repairs. Performance management, on the other hand, involves collecting performance measurements from various network elements, O&M units etc. to the network management system, and subsequently analyzing the collected data. Thus e.g. trends and problems in the network can be detected. However, in a typical prior art system fault management and performance management are separate from each other, and thus e.g. root cause analysis typically cannot be satisfactorily performed.
The collected performance measurements typically relate to parameters which can be used to indicate the performance of the network or a network element, or a service provided by the network. Such parameters are also referred to as performance indicators in the art. Examples of performance indicators include number of call attempts, number of blocked calls, number of dropped calls, handover failure rates, delay associated with a given connection, and throughput associated with a given connection, as well as measurements like memory usage, CPU usage, process status etc. The performance measurements are typically transmitted to the network management system sequentially, e.g. every 15, 30 or 60 minutes or every 12 or 24 hours, depending on the network, e.g. the network size, the amount of different kind of measurements to be collected, and the capacity of the network management system. Having received the collected performance measurements, the network management system analyzes them. Typically the analysis is performed by batch processing in which the received data is analyzed e.g. once every 24 hours.
Current implementations typically use e.g. various algorithm based methods for the analysis. A performance indicator has a range of values associated with it. Based on measurements collected over a relatively long time, a normal value or sub-range of values for a given performance indicator may be determined. Correspondingly, based on recently collected measurements, a current value for the same performance indicator may be determined. Thus, it may be determined for example, whether the current value deviates from the normal value enough for an operator to look into the matter.
Prior art also includes application WO 99/20034 of Rajala, Antti, filed Oct. 13, 1998, which is commonly assigned with the present application. The disclosure of this application is incorporated by reference herein. WO 99/20034 relates to monitoring and maintaining a network in telecommunications networks which comprise a large number of network elements. The network elements are presented as a hierarchical diagram or as a map display on a graphical user interface. The graphical user interface presents performance information of the network element as a graphical presentation in connection with the network element symbol in such a way that the operator can, at one glance, identify the network elements that are the most important in terms of the operation of the network or the network elements most affected by faults. The measurement results are post processed by a network management system when they are received, e.g. every 15, 30 or 60 minutes. Thus, WO 99/20034 fails to disclose a real time system. In addition, monitoring and maintaining as disclosed by WO 99/20034 requires a vast amount of calculation capacity and database capacity.
As current networks continue to grow exponentially, there is more and more need for faster network management including monitoring of network resources, network services and services provided over the network. In particular, analysis of the collected performance measurements has proven problematic. Firstly, the current implementations typically perform the analysis as an off-line procedure, for example once every 24 hours. In other words, the analysis is not performed in real-time which may seriously degrade the performance of the network or the quality of service since performance problems may remain unattended to until the next batch processing of collected performance measurements. Furthermore, the present algorithm based analysis methods do not allow real-time decision making and monitoring either. Typically, current algorithm based methods use 1,000-10,000 CPU cycles to calculate a specific response. And further, the current implementations do not allow real root cause analysis due to separate fault management and performance management, and due to a vast amount of calculation capacity required from such an analysis system if implemented on top of current implementations.
Therefore, the object of the present invention is to alleviate the problems described above and to introduce a solution that allows analysis and monitoring for a communications network, network resources, network services and services provided over the network significantly faster than previously, even in real-time.